Megaupload.com was taken offline by U.S. authorities and its founder and several company executives were arrested on charges of violating privacy laws.
Revenge attacks targeted sites for anti-piracy organisations RIAA and MPAA (America's Recording Industry Association and Motion Picture Association), record label Universal Music, and the Department of Justice.
Anonymous launched a massive cyber attack against U.S. government and anti-piracy websites yesterday in response to the shut down of one of the world's biggest file-sharing services.Scroll down for video
Held: Kim Dotcom, formerly known as Kim Schmitz and also known as Kim Tim Jim Vestor, was arrested along with three other executives of Megauploads. He is pictured here in 1999
Anonymous: The hackers' collective has launched a revenge attack
The sites were all disabled for some time yesterday.
There were reports that an Anonymous-affiliated Twitter account had boasted of the success of the attacks, but the profile had been removed by the time MailOnline checked today.
A statement posted on document sharing site Pastebin.com purportedly by Anonymous yesterday said: 'We Anonymous are launching our largest attack ever on government and music industry sites. Lulz.
'The FBI didn't think they would get away with this did they? They should have expected us.'
The statement also included home addresses and phone numbers for the MPAA chief executive, Chris Dodd, and details of the organisation's corporate offices.
Megaupload hosted large files and was often used to store mp3 music and digital video files, but claims most of its users used it as a legitimate file storage service.
The site had high-profile support from celebrities such as Kim Kardashian, Kanye West and P. Diddy, who made a video defending the site.
But its executives now face charges for costing copyright holders more than $500million in lost revenue from pirated films and other content.
A lawyer for Megaupload told the Guardian it would defend itself 'vigorously' against the charges and dismissed the criminal action as 'a civil case in disguise'.
Supporters: Swizz Beatz, pictured left with Alicia Keys, his wife, was listed as CEO of the company, and Kanye West, centre, and Kim Kardashian, right, were known fans of the site
News of the indictment comes just one day after websites including Wikipedia and Craigslist shut down in protest of two congressional proposals intended to thwart online piracy.
The Justice Department said in a statement said that Kim Dotcom, formerly known as Kim Schmitz, and three others were arrested in New Zealand at the request of U.S. officials.
Three other defendants are still at large.
If found guilty of the charges, each of the accused Megaupload executives could face up to 50 years in prison.
Megaupload was unique not only because of its massive size and the volume of downloaded content, but also because it had high-profile support from celebrities, musicians and other content producers who are most often the victims of copyright infringement and piracy.
The site now appears to be back online under a new domain name, declaring: 'This is the NEW MEGAUPLOAD SITE! we are working to be back full again' [sic].
The website boasted of endorsements from Kim Kardashian, Alicia Keys and Kanye West, among others.
The Hong Kong-based company listed rapper Swizz Beatz, a musician who married Keys in 2010, as its CEO.
In the dock: Megaupload executive Bram van der Kolk, left, Finn Batato, second from left, Mathias Ortmann and founder, former CEO and current chief innovation officer Kim Dotcom, right, appear in North Shore District Court in Auckland, New Zealand
Taken down: The Megaupload.com homepage boasted the endorsement of a string of high-profile celebrities
Indicted by the Department of Justice: Kim Dotcom was arrested in New Zealand and the other two executives of the company are on the run
Before the site was taken down, it posted a statement saying allegations that it facilitated massive breaches of copyright laws were ‘grotesquely overblown’.
THE MEGAUPLOAD SEVEN: THE EXECUTIVES INDICTED BY THE DoJ
- Kim Dotcom, aka Kim Schmitz and Kim Tim Jim Vestor, 37, a resident of both Hong Kong and New Zealand, who is the founder of Megaupload Limited and director and sole shareholder of Vestor Limited, which holds his ownership interests in the Mega-affiliated sites
- Finn Batato, 38, a citizen and resident of Germany, who is the chief marketing officer;
- Julius Bencko, 35, a citizen and resident of Slovakia, who is the graphic designer;
- Sven Echternach, 39, a citizen and resident of Germany, who is the head of business development;
- Mathias Ortmann, 40, a citizen of Germany and resident of both Germany and Hong Kong, who is the chief technical officer, co-founder and director;
- Andrus Nomm, 32, a citizen of Estonia and resident of both Turkey and Estonia, who is a software programmer and head of the development software division;
- Bram van der Kolk, aka Bramos, 29, a Dutch citizen and resident of both the Netherlands and New Zealand, who oversees programming and the underlying network structure for the Mega conspiracy websites.
‘The fact is that the vast majority of Mega's Internet traffic is legitimate, and we are here to stay. If the content industry would like to take advantage of our popularity, we are happy to enter into a dialogue. We have some good ideas. Please get in touch,’ the statement said.
A lawyer who represented the company in a lawsuit last year declined to comment Thursday.
Megaupload is considered a ‘cyberlocker,’ in which users can upload and transfer files that are too large to send by email. Such sites can have perfectly legitimate uses.
But the Motion Picture Association of America, which has campaigned for a crackdown on piracy, estimated that the vast majority of content being shared on Megaupload was in violation of copyright laws.
The website allowed users to download films, TV shows, games, music and other content for free, but made money by charging subscriptions to people who wanted access to faster download speeds or extra content.
The website also sold advertising.
The indictment was returned in the Eastern District of Virginia, which claimed jurisdiction in part because some of the alleged pirated materials were hosted on leased servers in Ashburn, Virginia.
Dotcom, a resident of both Hong Kong and New Zealand, and a dual citizen of Finland and Germany, made more than $42 million from the conspiracy in 2010 alone, according to the indictment.
Dotcom is founder, former CEO and current chief innovation officer of Megaupload.
